If you change a data type in the outputservice, it is a major change.
如果在输出服务中改变数据类型，那可是个重大改变。
2
So to avoid a major change, the outputservice implementation will have to convert from the new data types to the old data types before returning them.
因此要避免重大改变，输出服务实现将在返回之前从新数据类型转变为旧数据类型。
3
One option to ease this issue for the outputservice might be to have an explicit version parameter on the operations or an explicit version field on the complexTypes.